The present invention relates generally to apparatus and method for electrocoagulation, and particularly to electrocoagulation of varicose veins.
Many treatments of varicose veins are known. These treatments may be divided into two large categories, surgical and non-surgical. Surgical methods include, among others, removal of veins, ligation of veins and induced constriction of veins so as to re-direct flow of blood to alternate, non-varicose veins. The latter form of treatment includes electrically induced coagulation, also called electrocoagulation.
Prior art methods for electrocoagulation of veins include German Patent 4,414,807 which describes an electrosurgical instrument for localized varicose vein coagulation. The instrument has two fork-like protruding needle electrodes which may be inserted into a vein. High frequency current is then supplied to the electrodes, thereby causing coagulation of the vein.
Swiss Patent 684,157 describes an electrocoagulation instrument for localized varicose vein coagulation. The instrument has a heated electrode which includes a long tubular metal needle covered with a thermo-resistant insulating material. As in the previous patent, the electrodes may be inserted into a vein and high frequency current may be applied thereto to cause coagulation of the vein.
U.S. Pat. No. 5,047,028 describes a balloon catheter for electrocoagulation of varicose veins. The balloon catheter is introduced into a body cavity of a vein site and includes a plating wire which forms one electrode. A second electrode consists of a large plate placed on the chest of a patient. Electrical connection between the electrodes is made by filling the balloon with a conducting expansion fluid, preferably a liquid or gel-like medication vehicle charged with a medication. The balloon has a wall which is semi-permeable to the conducting fluid. The expansion fluid upon permeating the wall, ensures a fixed electrical resistance between the second electrode and the surface of the body cavity.
The present invention seeks to provide novel apparatus and methods for electrocoagulation. Although the present invention will be described with reference to electrocoagulation of varicose veins, it is appreciated that electrocoagulation of other vessels, growths, tumors or organs is in the scope of the present invention.
In accordance with a preferred embodiment of the present invention, an array of RF energized needles are arranged in an orderly or random fashion on a substrate of a ringed housing. The needles are pressed against a site to be electrocoagulated, such as a site of varicose veins. Pairs of needles are energized in any pattern by an RF generator. The pairs of needles act as electrodes and the energy that passes between the needles causes electrocoagulation of the vein site. Any pattern of varicose veins may be electrocoagulated, unlike the prior art which merely uses a pair of needles which may be ineffective in treating complicated clusters of varicose veins.
There is thus provided in accordance with a preferred embodiment of the present invention electrocoagulation apparatus including an array of more than two RF energized needles, and an RF generator for selectively energizing at least two of the needles so that energy passes therebetween. The needles may be arranged in rows, and the rows may be staggered. Alternatively, the needles may be arranged in a matrix of rows and columns. The needles may be generally equally spaced from each other or randomly arranged. Preferably the needles are spaced from each other corresponding to a width of a vein.
In accordance with a preferred embodiment of the present invention the needles are attached to a ring which at least partially circumscribes the needles.
Further, in accordance with a preferred embodiment of the present invention the ring includes a strap attachable to a limb of a patient.
Still further in accordance with a preferred embodiment of the present invention at least one of the needles is hollow to allow passage therethrough of a substance.
There is also provided in accordance with a preferred embodiment of the present invention a method for electrocoagulation including placing an array of more than two RF energized needles against epidermis of a patient at a site to be electrocoagulated, selecting at least two of the needles to pass energy therebetween, and transmitting RF energy to tips of the selected needles so as to cause electrocoagulation at the site.
In accordance with a preferred embodiment of the present invention the step of placing includes pressing the needles against the epidermis so as to cause a vein to be located between tips of adjacent needles.
Further in accordance with a preferred embodiment of the present invention the step of placing includes pressing the needles against the epidermis so as to cause the epidermis to bulge inwards of a space formed between tips of adjacent needles.
Still further in accordance with a preferred embodiment of the present invention the needles are arranged in rows and the step of transmitting includes energizing pairs of the needles, the pairs including two needles selected from the same row.
Additionally in accordance with a preferred embodiment of the present invention the needles are arranged in rows and the step of transmitting includes energizing pairs of the needles, the pairs including two needles selected from different rows.
Further in accordance with a preferred embodiment of the present invention the step of transmitting includes energizing pairs of the needles in a zigzag pattern.
In accordance with a preferred embodiment of the present invention, the transmitting of RF energy includes a high frequency shaped train of pulses, typically, but not necessarily, in the range of 200 KHz to 1 MHz, and preferably with an intensity of up to 100 W. Preferably the duration of the pulses is approximately 10-40 msec, the duration changing in correspondence with the frequency and intensity of the pulses.
Additionally in accordance with a preferred embodiment of the present invention, RF energy is transmitted to a site downstream of the electrocoagulation site.
Further in accordance with a preferred embodiment of the present invention, a substance may be introduced through the RF energized needle, for example, a coagulating agent and a substance which enhances electrical flow.